What can I use to make clear dish soap thicker?

I want to paint with something 100% clear and quite viscous. I added food coloring to transparent dish soap and that is so far the best solution to a clear paint body, but I want to make it thicker. I found a list of common ingredients in dish soap here, and I may be mistaken but I figured if I knew which ingredient is a thickening agent that doesn't increase opacity, I could simply add more of it to the dish soap and get a thicker gel.

From what I could find only the PPG (propylene glycol) and alkyl dimethyl amine oxide are thickeners. So I would like to know if any of you know the properties of these chemicals. How transparent are they and how viscous are they? And is it possible to buy in retail quantity? I found PPG on amazon but I'm not sure if it's the right thickness. I found this DOW link and I'd like to get my hands on their thickest product but of course I can't buy in bulk from DOW.

I've looked into other thickeners that are clear, stearic acid seems like my best bet and if anyone's worked with it before I'm wondering if I would have to melt it in with soap and generally how it performs generally.

You're painting with soap? Anyway, the dimethylamine oxide is one of the surfactants... not a thickener. The PPG/PEI/PEG copolymers are functional in surfactants formulations. They are wetting agents, emulsifiers and coupling agents. The real thickener wasn't given in that answer.

I just spent about 3 hours reading from that link. The Carbopol products look perfect. Would you know where to get their products at retail? The only retailer I could find is from here, I think I'll try them but they only have one carbopol formula, I want to try others mainly the ultrez 21 too.

The only other possibility involves making up a business name and asking the supplier for a sample (bad idea?)

I just spent about 3 hours reading from that link. The Carbopol products look perfect. Would you know where to get their products at retail? The only retailer I could find is from here, I think I'll try them but they only have one carbopol formula, I want to try others mainly the ultrez 21 too.

The only other possibility involves making up a business name and asking the supplier for a sample (bad idea?)

I don't think you'll find Carbopol at any retail stores. If you are limited to what you can find retail, and I include scientific supply houses as retail, I would use other polymers like polysaccharides (agar, alginate, carrageenan) or gelatin. You can make these compounds into as thick a solution as you want, even something as thick as a gummi (using gelatin). Here's an article that reports the unusual thickening of gelatin/anionic surfactant combinations. Sounds like it's right up your alley. In combination with gum arabic, gelatin can thicken in a spectacular way... all the way to gummi-like jelly. Dissolve the gum arabic in some water and combine small amounts of this dilute solution to the solution of gelatin.

I really like the Carbopol type thickening. It makes processing amazingly easy provided there aren't any multivalent metals in the formulation. Of course as a chemist I can get samples fairly easily. YMMV.